Technical Field
The present invention relates to an intake air quantity control device for an internal combustion engine, and particularly relates to an intake air quantity control device for an internal combustion engine, which controls an aperture ratio of a throttle valve by a driving unit including a drive motor.
Background Art
In conventional intake air quantity control devices in this family, there is a known intake air quantity control device in which a drive motor is assembled in a throttle body forming an intake air passage of an internal combustion engine, and a gear joined to a motor shaft of the drive motor is linked to a throttle shaft of a throttle valve, and the throttle shaft is rotated at an arbitrary angle by rotating the drive motor, whereby an aperture ratio of the throttle valve provided in the intake air passage is controlled.
In order to improve a vibration-proof capability of a conventional drive motor, an intake air quantity control device for an internal combustion engine, in which a component for damping a vibration (for example, a wave washer or the like) is provided between a bottom surface of the drive motor and a throttle valve, is disclosed (for example, refer to Patent Document 1).
Meanwhile, it has been a problem in recent years that various actuators must be miniaturized in order to reduce space in an engine room, so that there is a conventional system, as a countermeasure for solving the problem, in which an intake air quantity control device can be miniaturized by adopting a flat motor in which the outer diameter of the drive motor is partly flattened.